So you’re working more than a mile below the surface of the earth, and there’s a cave in. How do you let someone know you’re alive?

Mike Summerkamp: “Pounding on piping, or even shouting.”

That’s Mike Summerkamp, who spent 30 years working underground as an electrician at the Galena Mine. He says mines have wired phone systems, but …

Mike Summerkamp: “If there is anything close by him it’s probably 75 or 100 feet away.”

The company that owns the Lucky Friday Mine confirms that, and says the phone is likely around 150 feet away. The silver, lead, and zinc mine is rigged up with regular phones underground – like the land line you grew up with — plus, phones that act as pagers throughout the mine. Melanie Hennessey is a spokeswoman for Hecla Mining. She says Marek carried no personal communication device and her company doesn’t require one underground at the Lucky Friday.

Melanie Hennessey: “The communication system that is in place is what’s operational at that depth. And what is often found at an underground mine.”

But there are wireless systems that work at that depth underground. Mark Rose owns a company called Tunnel Radio in Corvallis that makes them.

Mark Rose: “Little handy talky units. At any point in the mine one guy can talk to another point.”

In industry jargon, the kind of system Rose’s company makes is called a “Leaky Feeder.” His is among several companies that make this technology. Rose says he’s installed it in silver mines similar to the Lucky Friday – including one in Alaska that’s owned by Hecla. He’s visited the Lucky Friday and estimates installing a Leaky Feeder system there would cost about 200-thousand dollars.

Mark Rose: “We have to lay a cable, a special cable, it’s the same technology used in buildings and subways.”

Jessica Robinson: “Would this kind of technology work at the level – you know, 6,000 feet down – that we’re talking at the Lucky Friday?”

Mark Rose: “No problem. Have it for lunch every day.”

Jessica Robinson: “That’s a yes?”

Mark Rose: “Yes.”

In fact, the Miner Act of 2006 that Congress passed in the wake of the Sago Mine disaster in West Virginia mandates that miners carry two-way wireless communication devices. The law also requires them to wear a tracking chip that can help rescuers locate them. But here’s the thing about that law:

Celeste Monforton: “Those regulations and that law only applied to underground coal mines.”

Not metal mines, says Celeste Monforton. She teaches at the George Washington University School of Public Health and used to work at the Mine Safety and Health Administration.

Celeste Monforton: “I have over the last five years often thought about the law and the next time there’s a disaster in a metal mine and people realize, ‘There’s no requirements for communication for metal miners?’”

So while the coal industry has been stringing cable through mines, and sending miners out with Motorola radios and chips in their helmets, industry experts say mines like the Lucky Friday have by-and-large stuck with communication systems that date back to the 1970s.

Mine industry attorney Ed Green says part of the reason for separate regulations is that metal mines face less of a risk of explosions.

Ed Green: “Politics being what they are, I think the focus of the Congress was on the matter at hand, which was an underground coal mine explosion.”

It’s not clear whether any two-way communication device would have helped Larry Marek after the Lucky Friday cave-in. And there’s still a question of how much damage such a system can sustain in a collapse or explosion.

Hecla Mining says the camera sent down into the cave-in area shows that there is a space, but so far there’s no sign of Marek.